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HomeMy WebLinkAbout2007 09 24 Informational 101 Noise Data Collection Seminole Expressway COMMISSION AGENDA ITEM 101 CONSENT INFORMATIONAL X PUBLIC HEARING REGULAR September 24, 2007 Meeting IY/ f, MGR / Y /DEPT Authorization ,0/ // REQUEST: Public Works Department providing the City Commission with information regarding the City's independent noise data collection on the Seminole Expressway (SR 417) PURPOSE: The purpose of this agenda item is to provide the City Commission with information regarding the City's independent noise data collection on the Seminole Expressway (SR 417) ISSUE OVERVIEW: . Florida's Turnpike recently completed a Project Development and Environment (PD&E) Study for the proposed widening of the Seminole Expressway (SR 417) from 4-lanes to 8-lanes from the Orange/Seminole County line to the Rinehart Road interchange. . A Noise Study was completed as a part of the PD&E Study by the Turnpike's engineering consultant, PBS&J. The Noise Study concluded that a noise barrier was not a reasonable abatement measure in Winter Springs where the Expressway borders Chelsea Woods, Chestnut Estates, and Seneca Bend (an Oviedo subdivision) because the cost per benefited residence exceeds the $35,000 upper limit established by FDOT. . In June 2007, the City hired Dr. John MacDonald to perform a technical review of the noise impact component of the Turnpike's PD&E report. Dr. Macdonald reviewed the study mcthodology and the abatement options that were considered, including the estimation of the number of benefited receivers and a review of the reasonableness criteria used to detennine whether noise abatement is appropriate. Dr. Macdonald also reviewed the Turnpike's Traffic Noise Model used to predict sound levels and noise banier impacts. . The City Commission received Dr. MacDonald's evaluation report as an informational agenda item at the August 13,2007 Commission meeting. The Commission directed Informational Agenda Item 101 September 24,2007 Page 2 of3 Staff to proceed with noise data collection to verify the Turnpike's noise model calibration. NOISE DATA COLLECTION SUMMARY: Dr. John MacDonald monitored sound pressure levels on September 5, 2007 at two locations along the Seminole Expressway. The fIrst location was in Chelsea Woods at Otisco Way, a location shown in the Turnpike's Noise Study to be one of the most severely impacted areas in Winter Springs. The second location was at Mikler Road, which is the same location the Turnpike used to collect noise data to calibrate the noise model. The Mikler Road location is in Seminole County, approximately halfway between Red Bug Lake Road and Aloma A venue. At both monitoring locations, sound levels were monitored for approximately eight hours, including portions of the morning and evening peak traffic periods. Trat1ic and meteorological data was also collected throughout the eight hour period. Dr. MacDonald's noise data collection procedures complied with the applicable FOOT guidelines. A copy of Or. MacDonald's Draft Report is attached as Exhibit A. Some key summary points from the noise data collection are as follows: . The measured sound levels at Mikler Road were consistent with the Turnpike's measured sound levels at the same location for the same time period (approximately 11 :00 AM). . Sound levels during the peak traffic periods were measured to be up to 5 dBA higher than the off-peak periods at both monitoring locations. . Sound levels measured at Otisco Way in Chelsea Woods were generally consistent with those at Mikler Road throughout the measurement period. FDOT SOUND WALL DECISION CRITERIA: The Turnpike utilizes a two-step process to detennine if a noise barrier is a reasonable abatement measure for a particular area: . STEP 1 - Is the area impacted? The minimum noise level for a residence to be considered impacted is 66 dBA. The Turnpike's Noise Study concluded that residences in Chelsea Woods, Chestnut Estates, and Seneca Bend will be impacted. After an area has been dctennined to be impacted, the decision on whether noise abatement is reasonable advances to Step 2. In the case of Chelsea Woods, Chestnut Estates, and Seneca Bend, no additional noise data collection or analysis is necessary regarding the number of impacted residences, or the severity of the noise impacts, because the area has already been determined to be impacted. Informational Agenda Item 101 September 24, 2007 Page 3 of3 . STEP 2 - If the area is impacted, are there enough benefited receivers such that the cost of a noise barrier does not exceed $35,000 per benefited receiver? A benefited receiver is defined as a site that would experience at least a 5 dBA noise reduction as a result of providing a noise barrier. The Turnpike's Noise Study concluded that 45 residences in Chelsea Woods, Chestnut Estates, and Seneca Bend would receive at least a 5 dBA reduction and therefore qualify as benefited receivers. The cost of a noise barrier per benefited receiver for the impacted residences is $48,636, which exceeds the $35,000 maximum specified by the FOOT's noise study manual. In this case, a total of 64 benefited receivers would be needed to be within the maximum cost criteria. Typically, only the homes within the first few rows of the highway will experience a 5 dBA or greater noise reduction when a noise barrier is installed. Therefore, the density of the residences closest to the highway is a critical factor in determining the number of benefited receivers. ADDITIONAL INFORMATION: Representatives from the Turnpike met with homeowners from Chelsea Woods, Chestnut Estates, and Seneca Bend on September 17,2007 to discuss the noise barrier issue. Approximately 90 residents attended the meeting. The Turnpike gave a brief presentation and then answered questions and listened to comments from the residents. All residents attending the meeting expressed a desire to have a noise barrier installed. The Turnpike reiterated their position that the area is impacted by noise, but the cost per benefited receiver exceeds the maximum allowed under FDOT criteria. The Turnpike agreed that the noise study would be re- perfonned at the design stage of the 8-lane widening project, which has not been programmed for funding at this time. FUNDING: The City has spent a total of $3,585 to-date for Dr. John MacDonald's services, consisting of $1,235 for the technical review of the Turnpike's Noise Study, and $2,350 for the collection and evaluation of noise data. A TT ACHMENTS: 1. Exhibit A - Sound Level Measurements of the SR 417 Corridor COMMISSION ACTION: Sound level Measurements of the S.R. 417 Corridor Draft Report Prepared for: Brian Fields City Engineer City of Winter Springs 1126 East S.R. 434 Winter Springs, Florida 32708 Prepared by: John M. MacDonald, Ph.D., P.E. 3142 Ash Park Loop Winter Park, Florida 32792 September 7, 2007 ,4 Draft Sound Level Report, J. MacDonald, PE, LLC Seminole Expressway (S.R. 417) Sound Pressure Levels September 7, 2007 Introduction The following report summarizes the results of environmental sound pressure level testing that occurred along the Seminole Expressway in the vicinity of Winter Springs, Florida. Sound pressure levels were monitored at two locations along the corridor between Aloma Avenue and S.R. 434 and in the vicinity of residences that border this roadway. The sampling took place on September 5,2007. The purpose of the sound level survey was to ascertain existing sound pressure levels caused by the Seminole Expressway in the course of a given day from morning rush hour to evening rush hour. Meteorological data was also collected to ensure that weather conditions did not exceed acceptable levels for sound level monitoring in accordance with ANSI guidelinesl. Methodology Sound level analyzers were positioned at two locations along the S.R. 417 corridor between Aloma Avenue and S.R. 434 to monitor sound pressure levels over an eight hour period. Type I sound level analyzers were used in this test (Cesva SC31 0) and were calibrated (Rion model NC-74 calibrator) and operated in accordance with FDOT and ANSIl guidelines including the use of windscreens. The analyzers measured one second Leq sound pressure levels for the duration of the measurement period. This data was used to compute hourly Leq levels for the eight hour time period. A technician was located at the measurement locations for the purpose of identifying sound sources other than the highway during the measurement period. These observer logs were used during data analysis to determine the source of specific loud acoustic events and to remove extraneous events such as commercial jet flyovers and resident noise from the data. Figure 1 depicts the S.R. 417 corridor and the measurement locations at Otisco Way west of the highway located in the Tuskawilla Communities area of Winter Springs and Mikler Road located east of the highway and near Aloma Avenue. I ANSI S1.13-1971 (1986), American National Standard, Methods/or the Measurement o/Sound Pressure Levels 2 The units are decibels (dB) and the descriptor (A) after dB indicates that the sound frequency bands have been weighted to simulate the response of the human ear. The descriptor Leq, is an acoustic average of the sound energy during a specified time period that represents the same acoustic energy as the time-varying value. Meters were set to a Slow time constant for exponential averaging. The acoustic signal is sampled 8 times per second and Lmax is the maximum sound pressure level within the 8 samples (assuming a one second sample rate). Draft Sound Level Report, J. MacDonald, PE, LLC 2 Figure 1. Aerial of S.R. 417 and Measurement Locations. Table 1 summarizes the sound level analyzer locations, their distances from the ROW and from the S.R. 417 nearest travel lane. Table 1 also contains the calibration levels of each analyzer and the start and end of the test period. Table 1. Measurement Locations. Location Distance from nearest S.R. 417 travel lane Sound Level Analyzer SOT* calibration level dB(A) EOT* calibration level dB(A) Mikler Road, 100 ft. from ROW fence Mikler Road, 150 ft. from ROW fence Otisco Way, 100 ft. from ROW fence *SOT = start of test; EOT = end of test 190 ft. Cesva SN:T219972 SN :T220281 Cesva SN :T219965 94.0 94.0 93.8 94.0 240 ft. 94.0 93.8 182 ft. Cesva SN:T220278 94.0 94.0 Draft Sound Level Report, J. MacDonald, PE, LLC 3 Recorded data was adjusted for calibration drift using the pre-event and post-event calibration levels noted in Table 1 (cal adjustment = {2*SPLret~SPLsorSPLEOT}/2). The analyzers measured one second Leq sound pressure levels for the duration of the measurement period. Meteorological conditions were monitored and recorded (at the Mikler Road location) to ensure that sound level data were collected under acceptable conditions. Data was not included in the analysis if wind speeds exceeded 5 m/sec. Winds were low throughout the test but there was intermittent rain that occurred at the Mikler Road location. Equipment was covered during rain events and calibration levels were checked to ensure that humidity was not causing adverse effects on the sound level analyzers and microphone/preamp systems. Appendix A contains meteorological information collected during the measurements. Measurement Results Sound pressure levels were recorded from 7:30 a.m. to 4:30 p.m. on September 5, 2007. Figures 2-4 are the time histories of the one second Leq sound pressure levels at each location. A rain event occurred at Mikler Road from 1:48 p.m. to 2:01 p.m. and again at 4: 15 p.m. which ended the test at the Mikler location. No rain events occurred at the Otisco Way site. 100 ft. from ROW fenceline-Mikler Rd. ;:t in "0 ,3 <I> '" 85 80 75 70 65 60 55 50 ,p ,p ,p ,p ,p ,p ~ ,p ,p ,p <<~ <<~ <<~ <<~ <<~ <<~ <<~ <<~ <<~ ~ .~ ~ .~ ~ ~ ~ ~ ~ ~ ~ ~ ~ .~ ~ ~ .~ ~ .~ .~~~~$Pfl#~~~~~~~~~~~ , v v ~, ~, "v "v "C). "". "". ,,'1,. ,,'1,. ". ". '1,. '1,. "0. "0. ~. ----~ Figure 2. Sound Pressure Level time history at Mikler Road, 100 f1. from ROW fcneeline. Draft Sound Level Report, J. MacDonald, PE, LLC 4 150 ft, from ROW fenceline-Mikler Rd. Sept. 5,2007 85 80 <( 75 00 "0 70 g 65 VI 60 . 55 50 ~~~~~~~~~~~~~~~~~~~~ ~,~~~~~~~~~~~~~~~~~~,~ '1,-' '0' Rl' 'b ~, '0' lx' ~' (\,' ", Rl' '0' ,.:\' '0 5:)' Ix (\, " ,5:) Q> ,," ,,~ qjG '0'" d.J'0 d.J~ "c::)\:! "c::)'? <,'0 ,,"':.> ,,<tG dV ,,<t'.J ",'Y ",Yj 't'V 'j,,~ ".)'!--' ':.>'J Ix", ---.---- Figure 3. Sound Pressure Level time history at Mikler Road, 150ft. from ROW fenceline. The Mikler Road results (Figures 2 and 3) show that sound pressure levels were generally louder in the morning rush hours by about 5 dB(A) and then remained constant (fluctuated about a similar mean value) throughout the day into the afternoon rush time period. A loud truck event on the highway is noticeable at the 1 :02 p.m. location in Figures 2 and 3. - 100 ft, from ROW fenceline-Otisco Way, Sept. 5, 2007 <( 00 "0 U CII VI 85 80 75 70 65. 60 55 50 ~~~~~~~~~~~~~~~~~~~~ ~ ,~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~'~.~'~~~~~~~ '\' '\ '0' '0' Q> Q> ~ ~ ~ ~ ~ ~ ~ ~' ~. ~ ~ ':.>' ~ ~' Figure 4. Sound Pressure Level time history at Otisco Way, 100ft. from ROW fenceline. The Otisco Way sound levels shown in Figure 4 indicate elevated levels [approximately 64 dB(A)] in the morning rush period, followed by an off-peak period that was about 4 dB(A) less than the morning peak. The sound levels increased again in the afternoon, corresponding to the beginning of the evening rush time period. Figure 5 plots the hourly LcqA levels at each site and Table 2 contains displays the LeqA levels in a tabular fonnat along with the calibration measurements noted in the Draft PD&E doeumene. ] "Draft Project Development and Environment Noise Study Report, Widening Seminole Expressway (SR 417) from South of Aloma Avenue to the Rinehart Road Interchange", Seminole County, Florida, Financial Project 10#417545-1, April 2007. Draft Sound Level Report, J. MacDonald, PE, LLC 5 Hourly Leq Values on 417 Corridor Sept. 5, 2007 70 ~ III 60 "0 65 -- Otisc~W~y~ L~qAhr "I Mikler. 100 ft.. LeqAhr -Mikler. 150 ft.. LeqAhr; 50 <0'0'0 ,\'0'0 ro'0'0 0;;'0'0 ,,'0'0'0 ",,'0'0 <j,,'0'0 <,:>'0'0 ,,">-'0'0 ,,<0'0'0 ,,<0'0'0 .:?'0 "ro'0'0 hour (1600 = 1600-1659) Figure 5. Hourly LeqA results from the measurement locations. Table 2. Hourly LeqA Measurements from this data collection effort and the results listed in the Draft PD&E document. Table 2 indicates that the measurements conducted on September 5, 2007 are similar to those measurements taken in March of this year (listed in the Draft PD&E). The Leq for the entire 11 :00 am hour on September 5,2007 (at the Mikler Road, 100 ft. location) was 61.1 dB(A) while the 10 minute readings from March 29,2007 were between 61.4 and 61.7 dB(A). This indicates that the 10 minute samples were a fairly accurate estimate for Draft Sound Level Report, J. MacDonald, PE, LLC 6 the full hour Leg. The Sept. 5, 2007 hourly measurements at the 150 ft. Mikler location were within 1 dB(A) of those reported in the Draft PD&E. Total traffic counts (sum of traffic in both directions) of S.R. 417 were manually taken by the observer at the Mikler Road location and Traffic speeds were estimated by "drive- thrus" of the corridor at various times during the day. Tables 3 and 4 detail those measurements. Figure 6 displays the traffic counts graphically and depicts the morning and afternoon increased traffic levels that were indicated in the time history graphs. Hourly S.R. 417 Estimates based on manual counts Vl !: o 5000 :;::l u ~ 4000. "C ~ 3000 .0 ~ 2000 o ~ Ui 1 000 C1l U ~ C1l > 0 .t .t .t .t <(~ <(~ <(~ <(~ <(~ .'0'0 .'0'0 .'0'0 '0'0 .'0'0 .'0'0 '0'0 .'0'0 .'0'0 '1". ~. co. '0 $:). '1" .<f. co. '0 '\" <0')) 0.)":5 \St>- .\:) ." 'S":5 ~t>- "'1,, ". '1" ~ Figure 6. Graph of Total Traffic (both directions, all lanes) counts on S.R. 417, Sept. 5, 2007. Draft Sound Level Report, J. MacDonald, PE, LLC 7 Conclusions This report has summarized the results of environmental sound pressure level testing that occurred along the Seminole Expressway (S.R. 417) in the vicinity of Winter Springs, Florida. Sound pressure levels were monitored at two locations along the corridor between Aloma A venue and S.R. 434 and in the vicinity of residences that border this roadway. The sampling took place on September 5, 2007. These measurements were conducted between 7: 12 a.m. and 4:30 p.m. Table 5 summarizes the findings of peak and off-peak hourly sound pressure levels (Leg) at these measurement locations. Table 5. Peak and off-peak sound levels at two geographic locations on the S.R. 417 Corridor Se 1. 5, 2007 . Otisco Way, 100 f1. from ROW I fence line 64 dB(A) 61 dB(A) 63 dB(A) These measurements were compared to those reported in the Draft PD&E Noise Study conducted as part of a widening project of this roadway. The reported sound pressure levels in the Draft PD&E were within 1 dB(A) of the measured hourly levels conducted during this work. The measurements listed in the Draft PD&E were conducted during anoff-peak time period (11 :08 to 11 :33 a.m.). This report demonstrated an approximate 5 dB(A) difference between morning Leg levels and the off-peak levels (hourly Leg). The sound levels began to increase in the afternoon and showed a similar p.m. msh hour trend. The measurements were scheduled to end at 4:30 p.m. but the Mikler Road location experienced rain at 4: 15 p.m. which ended the test at Mikler Road. Otisco Way measurements continued until 4:30 p.m. Draft Sound Level Report, J. MacDonald, PE, LLC to) Q) ~ E Appendix A Weather Data Wind Conditions at Mikler Road, Sept. 5, 2007 6 5 4 3 2 1 o ~ ~ ~ '?-~ ".'0'0 ",?'0'0 .'0'0 .v v< <0' 'b' ~~ ~~ ~~ ~~ " ~~ ~~ ~~ ~~ ~~ '0'0 '0'0'0'0 '0'0 .'0'0 .'0'0~'t.~. .";}<o ",1>:.'0' ~'t ~. 't. ";}. v< l~uw~n_d~~~ed, ~~sJ 8 Draft Sound Level Report, J. MacDonald, PE, LLC 9